High flow polyphenylene ether formulations with dendritic polymers

ABSTRACT

High flow polyphenylene ether formulations are obtained with the addition of dendritic polymers. High flow is also obtained with the addition of dendritic polymers to flame retardant polyphenylene ether formulations.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No.09/548,855 filed on Apr. 13, 2000, the entire contents of which areincorporated herein by reference.

BACKGROUND OF INVENTION

[0002] This invention relates to polyphenylene ether resins, and moreparticularly polyphenylene ether formulations with improved flow.

[0003] Polyphenylene ether resins (PPE) are an extremely useful class ofhigh performance engineering thermoplastics by reason of theirhydrolytic stability, high dimensional stability, toughness, heatresistance and dielectric properties. They also exhibit high glasstransition temperature values, typically in the range of 150° to 210°C., and good mechanical performance. This unique combination ofproperties renders polyphenylene ether based formulations suitable for abroad range of applications, which are well known in the art. Oneexample is injection-molded products, which are used for high heatapplications. Polyphenylene ether polymers typically have relativelyhigh molecular weights and possess high melt viscosity with intrinsicviscosity values typically greater than about 0.4 dl/g as measured inchloroform at 25° C.

[0004] One area in which polyphenylene ether based compositions hasrequired an improvement is melt flow capability, i.e. the ability toflow freely at elevated temperatures during various processing stagessuch as extrusion and molding. Poor melt flow can impact the size andtype of the part which can be prepared with the composition andinfluence the type of equipment in which the composition is processed.In U.S. Pat. No. 4,154,712 to G. Lee Jr. teaches that processability canbe improved by decreasing the molecular weight of the polyphenyleneether polymers; however, lower molecular weight sometimes adverselyaffects other properties such as impact strength. To aid processing,polyphenylene ether resins are often prepared with flow promoters, suchas polystyrene, saturated polyalicyclic resins and terpene phenol toreduce viscosity and impart high flow to the resulting composition.Polystyrene, terpene phenol and other such flow promoters reduce theheat deflection temperature (HDT) of the product and typically increasethe flammability of the PPE resin, as measured under UL94 standardprotocol.

[0005] Efforts to improve the flow characteristics of PPE resins withminimal or no loss of HDT values and impact other properties have beenmade. For example, U.S. Pat. No. 5,081,185 to Haaf et al. describescompositions comprising a blend of two or more polyphenylene etherresins with one resin having high intrinsic viscosity values of at leastabout 3.8 dl/g and the other having low intrinsic viscosity values of nogreater than 0.33 dl/g. The blend of the two PPE resins exhibits highermelt flow with no substantial decrease in heat deflection temperature(HDT) when compared to the high intrinsic viscosity PPE resin of theblend. In addition, U.S. Pat. No. 5,376,724 to Bailey et al. disclosespolyphenylene ether compositions, which contain a resinous additive thatimproves flow with only minor reductions in HDT values and impactstrength. The resinous additive is said to comprise vinyl aromaticmonomers such as sytrene monomers or a hydrocarbon compound containingat least 35 wt % aromatic units.

[0006] It is desirable to provide a PPE resin formulation with high flowcharacteristics with reduced loadings of flow modifier to minimize theimpact on HDT values, impact properties and flame retardance.

SUMMARY OF INVENTION

[0007] The present invention provides blends of polyphenylene etherresin, and dendritic polymers. It has been discovered that substantiallyequivalent improvements in the flow properties of compositionscontaining polyphenylene ether resins can be obtained with smalleramounts of dendritic polymers when compared to conventional flowmodifying additives.

DETAILED DESCRIPTION

[0008] The polyphenylene ether resin preferably has an intrinsicviscosity of at least about 0.35 dl/g, most often in the range of about0.4-0.6 dl/g, as measured in chloroform at 25° C. This polyphenyleneether resin can comprise one or more different polyphenylene etherpolymers. The dendritic polymers preferably have a melt viscosity in therange of 1 to 250 Pa at a temperature of 110° C. and shear rate of 30sec⁻¹. Preferably, the dendritic polymers are based on polyesters orpolyolefins. The compositions of this invention preferably contain atmost 15% by weight of the dendritic polymers. The weight ratio ofpolyphenylene ether resin to the dendritic polymer is preferably greaterthan 4:1.

[0009] The polyphenylene ether polymers of the polyphenylene etherresins used in compositions of the present invention are known polymerscomprising a plurality of aryloxy repeating units preferably with atleast 50 repeating units of Formula I

[0010] wherein in each of said units independently, each Q¹ isindependently halogen, alkyl (preferably primary or secondary loweralkyl containing up to 7 carbon atoms), aryl (preferably phenyl),halohydrocarbon groups (preferably haloalkyl) having at least twocarbons between the halogen atoms and the phenyl nucleus of Formula I,aminoalkyl, hydrocarbonoxy or halohydrocarbonoxy wherein at least twocarbon atoms separate the halogen and oxygen atoms and at least twocarbon atoms separate the halogen atoms and the phenyl nucleus ofFormula I.

[0011] Each Q² is independently hydrogen, halogen, alkyl (preferablyprimary or secondary lower alkyl up to 7 carbon atoms), aryl (preferablyphenyl), halohydrocarbon (preferably haloalkyl) having at least twocarbon atoms between the halogen atoms and the phenyl nucleus of FormulaI, hydrocarbonoxy groups or halohydrocarbonoxy groups wherein at leasttwo carbon atoms separate the halogen and oxygen atoms and at least twocarbon atoms separate the halogen atoms from the phenyl nucleus ofFormula I. Each Q¹ and Q² suitably contains up to about 12 carbon atomsand most often, each Q¹ is an alkyl or phenyl, especially C₁-C₄alkyl andeach Q² is hydrogen.

[0012] The term “polyphenylene ether resin,” as used in thespecification and claims herein, includes unsubstituted polyphenyleneether polymers, substituted polyphenylene ether polymers wherein thearomatic ring is substituted, polyphenylene ether copolymers and blendsthereof. Also included are polyphenylene ether polymers containingmoieties prepared by grafting onto the polyphenylene ether in a knownmanner such materials as vinyl monomers or polymers such as polystyrenesand elastomers, as described in U.S. Pat. No. 5,089,566 issued to S.Bruce Brown. Coupled polyphenylene ether polymers in which couplingagents such as low molecular weight polycarbonates, quinones,heterocycles and formals undergo reaction in the known manner with thehydroxy groups of two phenyl ether chains to produce a high molecularweight polymer are also included.

[0013] The polyphenylene ether polymers used in the compositions of thisinvention may also have various end groups such as amino alkylcontaining end groups and 4-hydroxy biphenyl end groups, typicallyincorporated during synthesis by the oxidative coupling reaction. Thepolyphenylene ether polymers may be functionalized or “capped” with endgroups, which add further reactivity to the polymer and in someinstances provide additional compatibility with other polymer systems,which may be used in conjunction with the polyphenylene ether polymersto produce an alloy or blend. For instance, the polyphenylene etherpolymer may be functionalized with an epoxy end group, a phosphate endgroup or ortho ester end group by reacting a functionalizing agent suchas 2-chloro-4(2-diethylphosphatoepoxy)6-(2,4,6-trimethyl-phenoxy)-1,3,5-trizene, with one of the endgroups of the polyphenylene ether polymer, i.e., one of the terminalhydroxyl groups.

[0014] It will be apparent to those skilled in the art from theforegoing that the polyphenylene ether polymers contemplated for use inthe present invention include all of those presently known, irrespectiveof the variations in structural units.

[0015] Specific polyphenylene ether polymers useful in the presentinvention include but are not limited to poly(2,6-dimethyl-1,4-phenyleneether); poly(2,3,6-trimethyl-1,4-phenylene) ether;poly(2,6-diethyl-1,4-phenylene) ether;poly(2-methyl-6-propyl-1,4-phenylene) ether;poly(2,6-dipropyl-1,4-phenylene) ether;poly(2-ethyl-6-propyl-1,4-phenylene)ether;poly(2,6-dilauryl-1,4-phenylene) ether; poly(2,6-diphenyl-1,4-phenylene)ether; poly(2,6-dimethoxy-1,4 phenylene) ether;poly(2,6-diethoxy-1,4-phenylene) ether;poly(2-methoxy-6-ethoxy-1,4-phenylene) ether;poly(2-ethyl-6-stearyloxy-1,4-phenylene) ether;poly(2,6-dichloro-1,4-phenylene) ether;poly(2-methyl-6-phenyl-1,4-phenylene) ether;poly(2-ethoxy-1,4-phenylene) ether; poly(2-chloro-1,4-phenylene) ether;poly(2,6-dibromo-1,4-phenylene) ether;poly(3-bromo-2,6-dimethyl-1,4-phenylene) ether; mixtures thereof, andthe like.

[0016] Suitable copolymers include random copolymers containing2,6-dimethyl-1,4-phenylene ether units and 2,3,6-trimethyl-1,4-phenyleneether units.

[0017] The polyphenylene ether resins employed in the compositions ofthis invention have an intrinsic viscosity greater than about 0.2 dl/g,as measured in chloroform at 25° C., and generally have a number averagemolecular weight within the range of about 3,000 to 40,000 and a weightaverage molecular weight in the range of 20,000 to 80,000, as determinedby gel permeation chromatography.

[0018] The polyphenylether ether polymers suitable for use in thisinvention may be prepared by any of a number of processes known in theart from corresponding phenols or reactive derivatives thereof.Polyphenylene ether resins are typically prepared by the oxidativecoupling of at least one monohydroxy aromatic compound such as2,6-xylenol or 2,3,6-trimethylphenol. Catalysts systems are generallyemployed for such coupling and contain at least one heavy metal compoundsuch as copper, manganese, or cobalt compounds, usually in combinationwith various other materials. Catalyst systems containing a coppercompound are usually combinations of cuprous or cupric ions, halide(e.g., chloride, bromide, or iodide) ions and at least one amine such ascuprous chloride-trimethylamine. Catalyst systems, which containmanganese compounds, are generally alkaline systems in which divalentmanganese is combined with such anions as halide, alkoxide or phenoxide.Most often, the manganese is present as a complex with one or morecomplexing and/or chelating agents such as dialkylamines,alkylenediamines, o-hydroxy aromatic aldehydes, o-hydroxyazo compoundsand o-hydroxyaryl oximes. Examples of manganese containing catalystsinclude manganese chloride-and manganese chloride-sodium methylate.Suitable cobalt type catalyst systems contain cobalt salts and an amine.

[0019] Examples of catalyst systems and methods for preparingpolyphenylether resins are set forth in U.S. Pat. Nos. 3,306,874,3,306,875, 3,914,266 and 4,028,341 (Hay); U.S. Pat. Nos. 3,257,357 and3,257,358 (Stamatoff); U.S. Pat. Nos. 4,935,472 and 4,806,297 (S. B.Brown et al.); and U.S. Pat. No. 4,806,602 issued to Dwayne M. White etal.

[0020] In general, the molecular weight of the polyphenylene etherresins can be controlled by controlling the reaction time, the reactiontemperature and the amount of catalyst. Longer reaction times willprovide a higher average number of repeating units and a higherintrinsic viscosity. At some point, a desired molecular weight(intrinsic viscosity) is obtained and the reaction terminated byconventional means. For example, in the case of reaction systems whichmake use of a complex metal catalysts, the polymerization reaction maybe terminated by adding an acid, e.g., hydrochloric acid, sulfuric acidand the like or a base e.g., potassium hydroxide and the like or theproduct may be separated from the catalyst by filtration, precipitationor other suitable means as taught by Hay in U.S. Pat. No. 3,306,875.

[0021] The term dendritic polymers is used herein refers to bothdendrimers and hyperbranched polymers known in the art. Dendrimers andhyperbranched polymers suitable for use in this invention are welldefined, highly branched macromolecules that radiate from a central coreand are synthesized through a stepwise repetitive branching reactionsequence. Those preferred herein are the star or starburst dendriticpolymers having a multifunctional core with radial branching units,which extend from the core. The repetitive branching sequence typicallyguarantees complete shells for each generation, lending to polymers thatare typically monodisperse. The synthetic procedures for dendriticpolymer preparation often provide nearly complete control over the size,shape, surface/interior chemistry, flexibility and topology. Thisinvention includes the use of dendritic polymers with complete andsymmetrical branches as well as incomplete and asymmetric branches. Anexample of a suitable synthesis method is to employ a multifunctionalcompound, such as ethylene diamine, as a core building block. Thismultifunctional core is first reacted with acrylonitrile to provide astructure with four nitrile groups. These nitrile groups are reduced toamine units to complete the first cycle. Further reaction cycles preparedendritic polymers with 8, 16, 32, 64, 128, etc. primary amino groups.The terminal ends of these branching units can be functionalized, ifdesired, with conventional functional units for dendritic polymers suchas hydroxy groups, epoxy groups and ether groups.

[0022] The weight average molecular weight of preferred dendriticpolymers can range from about 1,000 to about 21,000 and is preferablyfrom about 1,500 to about 12,000, as determined by gel permeationchromatography. When attempting to increase flow, the most preferredvalues are at the low end of the molecular weight range of from about1,500 to about 5,000. Preferably the polymers have a narrowpolydispersity of from about 1.3 to about 1.5 and a melt viscosity of 1to 250 Pa at a temperature of 110° C. and shear rate of 30 sec⁻¹. Thedendritic polymers used in the present invention can optionally befunctionalized either in the core or at the periphery of the branchingunits. Polar groups and non-polar may be bonded to the periphery of thedendritic polymers as desired, depending on the nature of thepolyphenylene ether formulation. Preferably, hydroxy and/or epoxy groupsare bound at the terminal ends of the dendritic polymers used in thisinvention.

[0023] The molecules that can be used as a core contain at least onefunctional group and preferably contain multiple functional groups.These include ammonia, methanol, polymethylene diamines, diethylenetriamine, triethylene tetramine, tetraethylene pentamine, linear andbranched polyethylene imine, methylamine, hydroxyethylamine,octadecylamine, polyaminoalkylarenes, heterocyclic amines such asimidazolines and piperidines, morpholine, piperazine, pentaerythritol,sorbitol, mannitol, polyalkylenepolyols such as polyethylene glycol andpolypropylene glycol, glycols such as ethylene glycol, polyalkylenepolymercaptans, phosphine, glycine, thiophenols, phenols, melamine andderivatives thereof such as melamine tris (hexamethylenediamine).

[0024] The branching units can comprise a variety of polymers, which arederived from units typically having two distinct functional groups atdifferent ends. Examples of these simple polymers include polyesters,polyethers, polyolefins, polythioethers, polyamides, polyetherketones,polyalkyleneimines, polyamidoamines, polyetheramides, polyarylenes,polyalkylenes, aromatic polyalkylenes, polyarylacetylenes andcombinations thereof. Examples of suitable dendritic polymers aredescribed in U.S. Pat. No. 5,530,092 (Meijer et al.); U.S. Pat. No.5,998,565 (Debrabander-Bandenberg et al.); U.S. Pat. No. 5,418,301 (Hultet al.) and U.S. Pat. No. 5,663,247 (Sorensen et al.).

[0025] Preferred dendritic polymers are based on polyesters. Those whichare most preferred are the dendritic polymers sold under the trademarkBOLTORN® available from Perstorp Specialty Chemicals, Perstorp, Sweden.Of this series, BOLTORN H20 and BOLTORN H30 dendritic polymers, whichare functionalized with hydroxy groups at the periphery, are preferredand have a weight average molecular weight in the range of about 1,000to about 4,000.

[0026] Suitable central initiator molecules for the polyester typedendritic polymers include cycloaliphatic or aromatic diols, triols,tetraols, sorbitol, manitol, dipentaerythritol, a monofunctional alcoholand an alkoxylate polymer having a molecular weight less than 2000.Examples of suitable diols include 1,3-propanediol, 1,2-propanediol,1,3-butanediol, 1,2-ethanediol, 1,4-butanediol, 1,5-pentanediol,1,6-hexanediol and polytetrahydrofuran.

[0027] Suitable polyester chain extenders are monofunctional carboxylicacids having at least two hydroxyl groups such as α,α-bis(hydroxymethyl)-propionic acid, α, α-bis(hydroxymethyl)-butyricacid, α, α, α-tris(hydroxymethyl)-acetic acid, α, α-bis(hydroxymethyl)-bularic acid, α, α-bis(hydroxymethyl)-propionic acid, α,β-dihydroxypropionic acid, heptonic acid, citric acid, d- or l-tartaricacid or α-phenylcarboxylic acids such as 3,5-dihydroxybenzoic acid.

[0028] The optional chain terminating agents, which can be used, includesaturated monofunctional carboxylic acids, saturated fatty acids,unsaturated monofunctional carboxylic acids, aromatic monofunctionalcarboxylic acids such as benzoic acid and difunctional or polyfunctionalcarboxylic acids or anhydrides thereof. An example is behenic acid.Terminal hydroxyl groups in the polyester chain extender can be reactedwith chain stoppers with or without functional groups. Suitablepolyester-based dendritic polymers are described in U.S. Pat. Nos.5,418,301 and 5,663,247.

[0029] Other suitable chain extenders include aliphatic di, tri orpolyhydroxyfunctional saturated or unsaturated monocarboxylic acids,cycloaliphatic di, tri or polyhydroxyfunctional saturated or unsaturatedmonocarboxylic acids, aromatic di, tri or polyhydroxyfunctionalmonocarboxylic acids, aliphatic monohydroxyfunctional saturated orunsaturated di, tri or polycarboxylic acids, cycloaliphatic monohydroxyfunctional saturated or unsaturated di, tri or polyhydroxycarboxylicacids and aromatic monohydroxy functional di, tri or polycarboxylicacids. The esters of the above acids are also suitable.

[0030] The dendritic polymer is preferably used in the compositions ofthis invention in an amount, which ranges from about 0.1 to about 15 wt% of the total composition to provide a useful balance of properties.More preferably, an amount of dendritic polymers from about 1 to about10 wt % of the total composition is used to improve flow and even morepreferably, from about 2 to about 6 wt % of the total composition andmost preferably from about 2 to about 4 wt % of the total composition isused to improve flow while minimizing the loss of HDT values. Althoughnot preferred, the dendritic polymer can be used in the compositions ofthis invention in amounts up to 30 wt %.

[0031] The compositions of this invention can be blended with othercomponents in amounts that vary widely. Most often the composition ofthis invention is employed in an amount in the range of about 5 to 95%by weight with additives and other resins making up the difference.However, this invention includes high flow compositions, which compriseexclusively polyphenylene ether resin and dentritic polymers. Othercomponents, which can be added to the compositions of this invention,include conventional additives and resins conventionally added to PPEformulations.

[0032] Various resins may be blended with the compositions of thisinvention such as vinyl aromatic resins, polyamides as disclosed in U.S.Pat. Nos. 5,981,656 and 5,859,130, polyarylene sulfides as disclosed inU.S. Pat. No. 5,290,881, polyphthalamides as disclosed in U.S. Pat. No.5,916,970, polyether amides as disclosed in U.S. Pat. No. 5,231,146 andpolyesters as disclosed in U.S. Pat. No. 5,237,005.

[0033] The vinyl aromatic resins within the compositions of thisinvention comprise polymers that contain at least 25% by weight ofstructural units derived from a monomer of the formula:(Z)_(p)—Ph—C(R³)═CH₂ where Ph is phenyl, R³ is hydrogen, lower alkyl orhalogen, Z is vinyl, halogen or lower alkyl and p is 0 to 5. These vinylaromatic polymers include homopolystyrene, polychlorostyrene,polyvinyltoluene, and rubber-modified polystyrene (sometimes referred toas “HIPS”) comprising blends and grafts with elastomeric polymers, aswell as mixtures of these materials. Styrene-containing copolymers suchas styrene-acrylonitrile copolymers (SAN), styrene-maleic anhydridecopolymers, polyalpha-methylstyrene and copolymers of ethylvinylbenzene,divinylbenzene are also suitable.

[0034] The vinyl aromatic polymers are prepared by methods wellrecognized in the art including bulk, suspension and emulsionpolymerization. The amount of vinyl aromatic resin present within thecompositions of this invention depends on the properties contemplatedand typically ranges from about 5% to 90% by weight, preferably fromabout 15% to about 60% by weight, based on the weight of the totalcomposition.

[0035] Examples of suitable polystyrene resins are generally known inthe art and are described for example in Chapter 3 of Organic PolymerChemistry, 2^(nd) edition K. G. Saunders, Chapman and Hall, 1988 and inU.S. Pat. No. 4,816,510, issued to John B. Yates, III.

[0036] The use of various additives, which may impart a variety ofattributes to the compositions of this invention, is also within thescope of this invention. Most additives are well known in the art, asare their effective levels and methods of incorporation. Examples ofsuch additives are impact modifiers, flame retardants, plasticizers,antioxidants, fillers, conductive fillers (e.g., conductive carbonblack, carbon fibers, stainless steel fibers, metal flakes and metalpowders) reinforcing agents, (e.g., glass fibers), stabilizers (e.g.,oxidative, thermal and ultraviolet stabilizers), antistatic agents,lubricants, colorants, dyes, pigments, drip retardants, flow modifiersand other processing aids.

[0037] Materials that enhance the impact strength of the compositions ofthis invention are not critical but are sometimes desirable. Suitablematerials include natural and synthetic elastomeric polymers such asnatural rubbers, synthetic rubbers and thermoplastic elastomers. Theyare typically derived from monomers such as olefins (e.g., ethylene,propylene, 1-butene, 4-methyl-1-pentene) alkenylaromatic monomers,(e.g., styrene and alphamethyl styrene) conjugated dienes (e.g.,butadiene, isoprene and chloroprene) and vinylcarboxylic acids and theirderivatives (e.g., vinylacetate, acrylic acid, alkylacrylic acid,ethylacrylate, methyl methacrylate acrylonitrile). They may behomopolymers as well as copolymers including random, block, graft andcore shell copolymers derived from these various suitable monomersdiscussed more particularly below.

[0038] Polyolefins which can be included within the compositions of thisinvention are of the general structure: C_(n)H_(2n) and includepolyethylene, polypropylene and polyisobutylene with preferredhomopolymers being polyethylene, LLDPE (linear low densitypolyethylene), HDPE (high density polyethylene) and MDPE (medium densitypolyethylene) and isotatic polypropylene. Polyolefin resins of thisgeneral structure and methods for their preparation are well known inthe art and are described for example in U.S. Pat. Nos. 2,933,480,3,093,621, 3,211,709, 3,646,168, 3,790,519, 3,884,993, 3,894,999,4,059,654, 4,166,055 and 4,584,334.

[0039] Copolymers of polyolefins may also be used such as copolymers ofethylene and alpha olefins like propylene and 4-methylpentene-1.Copolymers of ethylene and C₃-C₁₀ monoolefins and non-conjugated dienes,herein referred to as EPDM copolymers, are also suitable. Examples ofsuitable C₃-C₁₀ monoolefins for EPDM copolymers include propylene,1-butene, 2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene and3-hexene. Suitable dienes include 1,4 hexadiene and monocylic andpolycyclic dienes. Ratios of ethylene to other C₃-C₁₀ monoolefinmonomers can range from 95:5 to 5:95 with diene units being present inthe amount of from 0.1 to 10 mol %. EPDM copolymers can befunctionalized with an acyl group or electrophilic group for graftingonto the polyphenylene ether as disclosed in U.S. Pat. No. 5,258,455.

[0040] Polyolefins are typically present in an amount from about 0.1% toabout 10% by weight based on the total weight of the composition. Wherethe polyolefin is an EPDM, the amount is generally from 0.25% by weightto about 3% by weight of the composition.

[0041] Suitable materials for impact modification include conjugateddiene homopolymers and random copolymers. Examples includepolybutadiene, butadiene-styrene copolymers, butadiene-acrylatecopolymers, isoprene-isobutene copolymers, chlorobutadiene polymers,butadiene acrylonitrile polymers and polyisoprene. These impactmodifiers may comprise from about 1 to 30 weight percent of the totalcomposition.

[0042] A particularly useful class of impact modifiers with conjugateddienes comprises the AB (di-block), (AB)_(m)—R (di-block) and ABA′(tri-block) block copolymers. Blocks A and A′ are typically alkenylaromatic units and Block B is typically a conjugated diene unit. Forblock coploymers of formula (AB)_(m)—R, integer m is at least 2 and R isa multifunctional coupling agent for the blocks of the structure AB.

[0043] Also useful are core shell graft copolymers of alkenyl aromaticand conjugated diene compounds. Especially suitable are those comprisingstyrene blocks and butadiene, isoprene or ethylene-butylene blocks.Suitable conjugated diene blocks include the homopolymers and copolymersdescribed above and they may be partially or entirely hydrogenated byknown methods whereupon they may be represented as ethylene-propyleneblocks or the like and have properties similar to those of olefin blockcopolymers. The suitable alkenyl aromatics include styrene, alpha-methylstyrene, para-methyl styrene, vinyl toulene, vinyl xylene and vinylnapthalene. The block copolymer preferably contains from about 15 to 50%alkenyl aromatic units. Examples of triblock copolymers of this type arepolystyrene-polybutadiene-polystyrene (SBS), hydrogenatedpolystyrene-polybutadiene-polystyrene (SEBS),polystyrene-polyisoprene-polystyrene (SIS) and poly(alphamethylstyrene)-polyisoprene-poly(alpha methylstyrene). Examples ofcommercially available triblock copolymers are the CARIFLEX®, KRATON D®and KRATON G® series from Shell Chemical Company.

[0044] Also included are impact modifiers comprising a radial blockcopolymer of a vinyl aromatic monomer and a conjugated diene monomer.Copolymers of this type generally comprise about 60 to 95 wt %polymerized vinyl aromatic monomer and about 40 to 5 wt % polymerizedconjugated diene monomer. The copolymer has at least three polymerchains, which form a radial configuration. Each chain terminates in asubstantially nonelastic segment, to which the elastic polymer segmentis joined. These block copolymers are sometimes referred to as“branched” polymers as described in U.S. Pat. No. 4,097,550 and are usedin amounts analogous to other conjugated diene based impact modifiers.

[0045] The compositions of this invention can be rendered flameretardant with the use of flame retardant additives known in the artincluding halosubstituted diaromatic compounds such as2,2-bis-(3,5-dichlorophenyl)propane, as described in U.S. Pat. No.5,461,096 and phosphorous compounds as described in U.S. Pat. No.5,461,096. Other examples of halosubstituted diaromatic flame retardantadditives include brominated benzene, chlorinated biphenyl, brominatedpolystyrene, chlorine containing aromatic polycarbonates or compoundscomprising two phenyl radicals separated by a divalent alkenyl group andhaving at least two chlorine or two bromine atoms per nucleus, andmixtures thereof.

[0046] The preferred flame retardant compounds employed in thecompositions of the present invention are free of halogen. Thesepreferred compounds include phosphorous compounds selected fromelemental phosphorous, organic phosphonic acids, phosphonates,phosphinates, phosphinites, phosphine oxides such as triphenylphosphineoxide, phosphines, phosphites and phosphates. Typical of the preferredphosphorous compounds are those of the general formula: O═P—(OZ)₃, andnitrogen analogs of these phosphorous compounds. Each Z represents thesame or different radicals including hydrocarbon radicals such as alkyl,cycloalkyl, aryl, alkyl substituted aryl and aryl substituted alkyl;halogen, hydrogen, and combinations thereof provided that at least oneof said Qs is aryl. More preferred are phosphates wherein each Q isaryl. Other suitable phosphates include diphosphates and polyphosphateshaving the following formulae

[0047] wherein Ar is phenyl, biphenyl with a lower alkyl bridge ortriphenyl, each R₁ is independently hydrocarbon; R₂, R₆ and R₇ areindependently hydrocarbon or hydrocarbonoxy, each X¹ is either hydrogenmethyl, methoxy or halogen, m is an integer of from 1 to 4; and n is aninteger of from about 1 to 30. Preferably, each R₁ is independentlyphenyl or lower alkyl of from 1 to 6 carbon atoms and R₂, R₆ and R₇ areeach independently phenyl, lower alkyl of 1 to 6 carbon atoms, phenoxyor (lower) alkoxy of from 1 to 6 carbon atoms.

[0048] Examples of suitable phosphates include phenylbisdodecylphosphate, phenylbisneopentyl phosphate, phenylethylene hydrogenphosphate, phenyl-bis-3,5,5′-trimethylhexyl phosphate, ethyidiphenylphosphate, 2-ethylhexyl di(p-tolyl), phosphate, diphenyl hydrogenphosphate, bis(2-ethyl-hexyl) p-tolylphosphate, tritolyl phosphate,bis(2-ethylhexyl)-phenyl phosphate, tri(nonylphenyl) phosphate,phenyl-methyl hydrogen phosphate, di(dodecyl) p-tolyl phosphate,tricresyl phosphate, triphenyl phosphate, isopropylated triphenylphosphate, halogenated triphenyl phosphate, dibutylphenyl phosphate,2-chlorethyidiphenyl phosphate, p-tolyl bis(2,5,5′-trimethylhexyl)phosphate, 2-ethylhexyldiphenyl phosphate and the like.

[0049] The most preferred phosphates are triphenyl phosphate, thealkylated triphenyl phosphates, including isopropylated and butylatedtriphenyl phosphates, bis-neopentyl piperidinyl diphosphate, tetraphenylbisphenol-A diphosphate, tetraphenyl resorcinol diphosphate,hydroquinone diphosphate, bisphenol-A diphosphate, bisphenol-Apolyphosphate, mixtures of these compounds and derivatives of thesecompounds.

[0050] Suitable compounds containing a phosphorus-nitrogen bond includephosphonitrilic chloride, phosphorus ester amides, phosphoric acidamides, phosphonic acid amides, and phosphinic acid amides.Bis-phosphoramide materials derived from piperazine and hydroxyaromaticcompounds are especially useful.

[0051] The level of flame retardant added to the compositions of thisinvention can range from 0.5 to 30 wt %. A preferred level for thephoshorous flame-retardants is from 9% to 17% by weight of thecomposition. In some embodiments it is preferable to use the phoshorousflame-retardants such as triphenyl phosphate in combination with otherflame-retardants such as hexabromobenzene and optionally antimony oxide.

[0052] Suitable phosphorous flame retardant additives are commerciallyavailable and methods for preparing the phosphate flame-retardants aregenerally known in the art. As an example, the compounds may be preparedby reacting a halogenated phosphate compound with various dihydric ortrihydric phenolic compounds until the desired number of phosphatefunctional groups are obtained. Examples of the phenolic compounds aredihydroxy aromatic compounds such as resorcinol and hydroquinone.

[0053] As reinforcing agents, the compositions of the present inventionmay contain fiber reinforcement such as glass fibers, which greatlyincreases the flexural strength and modulus as well as the tensilestrength of the molded composition obtained therewith. In general,lime-aluminum borosilicate glass that is relatively soda-free (“E”glass) is preferred. Although glass roving may be used, cut fibers areoften preferred. The length of such fibers is usually at least 3 mm anda preferred length is in the range of 3 mm to 13 mm. A preferreddiameter of the fibers is in the range of about 0.002 mm to about 0.01mm. The amount of glass fiber employed can range from 0 to 60% by weightof the total composition and is preferably in the range of about 3% to30% by weight based on the weight of the entire composition. Largeramounts are used where the end use requires a higher degree of stiffnessand strength. More preferably, the amount of glass fiber ranges fromabout 6% to 25% by weight. Carbon fibers, carbon fibrils, Kevlar® fibersand stainless steel fibers and metal coated graphite fibers can also beemployed at levels of 0 to 60 wt % preferably in the range of 3 to 25 wt%, more preferably in the range of 7% to 10% by weight. Carbon fiberstypically have a length of at least 3 mm, preferably from 3 mm to 13 mm.Samples of metal used to coat the graphite fibers include nickel,silver, brass, copper and gold, with nickel being preferred. Fibers andplatelets of metals such as aluminum, nickel, iron and bronze are alsosuitable in amounts up to 60 wt %.

[0054] Suitable non-fiberous inorganic fillers include mica clay, glassbeads, glass flakes, graphite, aluminum hydrate, calcium carbonate,silica kaolin, barium sulfate, talcum and calcium silicate(Wollastonite). Effective amounts will differ according to theparticular agent used, but they are generally in the range of 0.25 to 60wt % more typically from 1 to 30 wt % and preferably from 3% to 12% byweight based on the weight of the entire composition. Examples of micainclude muscovite, phlogopite, biotite, fluorophlogopite, and syntheticmica. Levels of mica are preferably in the range of 0.25% to 30% byweight, based on the weight of the entire composition. Preferred amountsof clay range from 0.25% to 30% by weight, based on the weight of theentire composition.

[0055] Suitable pigments include those well known in the art such asTiO₂, and carbon black. Suitable stabilizers include zinc sulfide, zincoxide and magnesium oxide.

[0056] While the compositions of this invention preferably are of areduced viscosity and increased flow, it is contemplated thatconventional flow promoters and plasticizers may still be desired forcertain embodiments. Examples of suitable flow promoters andplasticizers include the phosphate plasticizers such as cresyl diphenylphosphate, triphenyl phosphate, tricresyl phosphate, isopropylated andtriphenyl phosphate. Chlorinated biphenols and mineral oil are alsosuitable. When used, the plasticizers are typically employed in anamount of 1-15 wt % based on the weight of the composition.

[0057] Suitable antioxidants include hydroxylamines, hindered phenolssuch as alkylated monophenols and polyphenols, benzofuranones such as3-arylbenzofuranone, alkyl and aryl phosphites such as 2,4-di-tert butylphenol phosphite and tridecyl phosphite, and hindered amines such asdioctyl methylamine oxide and other tertiary amine oxides. Suchantioxidants are preferably used in an amount of 0.1 to 1.5 wt %, basedon the weight of the composition. Suitable U.V. stabilizers include4,6-dibenzoyl resorcinols, alkanol amine morpholenes and benzotriazole.

[0058] The compositions of this invention may be prepared by well-knownprocedures. A preferred method of preparation is to first dry blend thepolyphenylene ether resin and dendritic polymers and compound themixture by known techniques such as within an extruder to form a blend.The composition has a reduced viscosity and increased flow as comparedto polyphenylene ether resin alone without a significant reduction inHDT values. This composition can be blended with other components orextruded, quenched and chopped into pellets. These pellets can then bemelted and molded into articles of a desired shape and size orcompounded again to blend with other components before additionalprocessing in preparing finished articles.

[0059] Without further elaboration, it is believed that one skilled inthe art can, using the preceding description, utilize the presentinvention to its fullest extent. The entire disclosure of all patents,and publications cited above, are herein incorporated by reference.

EXPERIMENTAL

[0060] The examples, comparative examples and controls were prepared bycompounding the components identified in Tables 1-4 in a 30 mm Wernerand Pfeiderer co-rotating twin screw extruder operating at a temperatureof 550° F. (288° C.) with a speed of about 350 rpm. The extrudate wasquenched with water and pelletized. The pellets were injection moldedusing a Van Dorn Demag 120 ton injection molding machine (melttemperature 560° F. (290° C.) mold temperature 190° F. (88° C.)) intovarious specimens/test bars for UL90 flame out tests, HDT values andvarious physical properties. The polyphenylene ether was PPO® resin(poly(2,6-dimethyl-1,4-phenylene)ether) available from GE Plastics. Thepolystyrene was GEH1897 high impact polystyrene available from GEPlastics and comprising butadiene rubber. The impact modifier wasKraton® D1101 styrene-butadiene-styrene block copolymer, available fromShell Chemical Co. The Boltron® H20 and Boltron® H30 dendritic polymerswere obtained from Perstorp AB, Perstorp Sweden and comprise polyesterbased dendritic poloymers with hydroxy terminal groups. Nirez® 2150/7042flow modifier is a terpene phenol available from Arizona Chemical Co.used in the comparative examples. ZnO and ZnS were used as stabilizersin each formulation. The flame retardant formulations also contained thefollowing: FR-RDP tetraphenyl-resorcinol diphosphate flame retardant,available from Akzo Chemical and Nagase America Co., linear low densitypolyethylene (LLDPE) available from Millenium Petrochemicals, tridecyldiphosphite (TDP) stabilizer, available from GE Specialty Chemicals andfiller Teflon fibrils encapsulated with polystyrene-acrylonitrile(TSAN), available from GE Plastics, Netherlands. The amounts utilizedfor each formulation appears in Tables 1-4.

[0061] Heat distortion temperature at 264 psi (⅛ inch) was determinedaccording to the standards in ASTM-D648. Notched Izod was determined bythe standards set forth in ASTM-D256 and “Total energy” to failure wasdetermined by standards set forth in ASTM-D3763. Flexural modulus wasdetermined by standards set forth in ASTM-D790, and tensile strength wasdetermined by standards set forth in ASTM-D638. Five bars were testedfor each formulation and the average reported in the Tables except forflexural modulus, where 3 bars were tested and averaged and flammabilityhere 10 bars were tested and averaged for most values. Shear viscositywas measured using a Kayeness capillary rheometer.

COMPARATIVE EXAMPLES A-F and CONTROL X

[0062] Comparative Examples A-F and Control X are set forth in Table 1.Control X contains no flow modifier and Comparative Examples A-F employNirez terepene phenol flow modifier. TABLE 1 Formulation X A B C D E F.46 IV PPO resin 50 48 44 40 50 50 50 SBS, D1101 5 5 5 5 5 5 5 ZnS 0.10.1 0.1 0.1 0.1 0.1 0.1 ZnO 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Nirez 2150/70422 6 10 2 6 10 Boltron H20 Boltron H30 PS, HIPS GEH 45 45 45 45 43 39 351897 HDT @ 264 psi 245 238 234 235 240 242 251 (1/8″) ° F. Notched Izod,73F 4.52 4.82 4.94 4.49 4.39 4.38 4.56 ft-lb/in Total Energy, 73F 39.936.4 33.5 31.5 39.9 39.5 34.0 ft-lb Flexural Modulus, 347 357 340 338352 349 352 73F (1/8″) kpsi Flexural Str. @ 13,660 14,130 13,530 13,43014,670 14,890 15,060 yield, 73F (1/8″) psi Tensile Str. @ 8,230 8,1907,880 7,730 8,510 8,520 8,660 yield, 73F 2 in/m/in, psi T. Strength @7,240 7,160 6,890 6,680 7,330 7,250 7,230 break 73F 2 in/m/in, psi T.Elongation @ 3.93 3.89 3.46 3.20 3.84 3.85 3.76 yield, 73F 2 in/m/in, %T. Elongation @ 27.6 30.1 29.5 31.3 27.3 26.4 20.5 break, 73F 2 in/m/in,% Kayeness Rheology @ 300C Position, Pa-s Rate (1/s)  100 1009.2 932.2681.09 515.3 1012.7 858.9 747.6  500 432.4 396.6 307.8 237.5 428.4 382.1338.2 1000 286.5 262.8 207.3 160.9 281.6 255.7 228.9 1500 222.3 203.1162.1 126.1 217.4 199.2 179.6

EXAMPLES 1-6 and CONTROL Y

[0063] Examples 1-6 and Control Y are set forth in Table 2. Control Ycontains no flow modifier and Examples 1-6 employ BOLTRON H20 dendriticpolymer as a flow modifier. TABLE 2 Formulation Y 1 2 3 4 5 .46 IV PPOresin 50 48 44 40 50 50 SBS, D1101 5 5 5 5 5 5 ZnS 0.1 0.1 0.1 0.1 0.10.1 ZnO 0.1 0.1 0.1 0.1 0.1 0.1 Nirez 2150/7042 Boltron H20 2 6 10 2 6Boltron H30 PS, HIPS GEH 45 45 45 45 43 39 1897 HDT @ 264 psi 248 242241 232 247 245 (1/8″) ° F. Notched Izod. 73F 4.53 4.80 5.12 NO 4.405.60 ft-lb/in Total Energy, 73F 44.0 42.4 19.1 34.8 13.0 ft-lb FlexuralModulus, 347 342 320 292 336 323 73F (1/8″) kpsi Flexural Str. @ 14,84014,390 13,350 10,670 13,610 13,350 yield, 73F (1/8″) psi Tensile Str. @8,460 8,100 7,520 5,810 7,990 8,150 yield, 73F 2 in/m/in, psi T.Strength @ 7,330 7,080 6,730 5,720 7,010 7,110 break 73F 2 in/m/in, psiT. Elongation @ 3.86 3.68 3.51 2.40 3.89 3.77 yield, 73F 2 in/m/in, % T.Elongation @ 26.8 30.4 25.1 9.6 33.3 36.4 break, 73F 2 in/m/in, %Kayeness Rheology @ 300C Position, Pa-s Rate (1/s)  100 1017.1 764.1479.9 212.1 776.4 447  500 437.2 343.1 168.9 45.4 353 164.3 1000 289.1230.3 99.8 26.1 236.2 107.4 1500 223.8 179.7 71.8 19.5 183.5 83.9

EXAMPLES 7-10

[0064] Examples 7-10 are set forth in Table 3. Examples 7-10 employBOLTRON H30 dendritic polymer as a flow modifier. [t3] TABLE 3Formulation 7 8 9 10 .46 IV PPO resin 48 44 50 50 SBS, D1101 5 5 5 5 ZnS0.1 0.1 0.1 0.1 ZnO 0.1 0.1 0.1 0.1 Boltron H30 2 6 2 6 PS, HIPS GEH 4545 43 39 1897 HDT @ 264 psi 245 237 246 250 (⅛″) ° F. Notched Izod, 73F. 4.40 5.27 4.40 5.42 ft-lb/in Total Energy, 73 F. 31.3 14.9 29.2 18.1ft-lb Flexural Modulus, 334 314 333 321 73 F. (⅛″) kpsi Flexural Str. @14,140 12,990 14,270 13,700 yield, 73 F. (⅛″) psi Tensile Str. @ 7,7307,400 7,930 8,030 yield, 73 F. 2 in/m/in, psi T. Strength @ 6,880 6,6806,960 7,000 break 73 F. 2 in/m/in, psi T. Elongation @ 3.53 3.35 3.833.84 yield, 73 F. 2 in/m/in, % T. Elongation @ 31.4 28.3 33.2 33.9break, 73 F. 2 in/m/in, % Kayeness Rheology @ 300 C. Position, Pa-s Rate(1/s)  100 741.9 280.8 803.3 293  500 334.9 94.7 365.8 111.2 1000 225.172.5 247.3 84.4 1500 175.7 65.1 193.8 74.7

[0065] A comparison of the data in Table 1 to the data in Tables 2 and3, shows the addition of dendritic polymer to a polyphenylene etherformulation provides significantly higher reductions in Kayenessrheology at similar loadings to the Nirez 2150/7042 terpene phenol flowmodifier. Amounts of dendritic polymer as low as 2% wt show significanteffects in reducing viscosity and increasing flow. Heat distortiontemperatures do not vary significantly until much higher loadings (10%wt) were introduced. The data also show that impact properties werereduced, but to acceptable levels, particularly at lower concentrationsof the dendritic polymer.

EXAMPLES 11-22, COMPARATIVE EXAMPLES G-F and CONTROLS Q and R

[0066] The compositions for Examples 11-22, Comparative examples G-L andControls Q and R are set forth in Table 4. Examples 11-22 employ eitherBOLTRON H20 or BOLTRON H30 dendritic polymer as a flow modifier.Comparative examples G-L employ Nirez terpene phenol as an impactmodifier and Controls Q and R do not contain any flow modifier. TABLE 4FORMULATION Q G H I R J K L 11 12 .46 IV PPO 50.5 48.5 44.5 40.5 50.550.5 50.5 50.5 48.5 44.5 SBS, Kralon D1101 2.4 2.4 2.4 2.4 2.4 2.4 2.42.4 2.4 2.4 LLDPE 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 TDP 0.4 0.40.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 ZnS 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.10.1 ZnO 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 TSAN 0.2 0.2 0.2 0.2 0.20.2 0.2 0.2 0.2 0.2 Nirez 2150/7042 2 6 10 2 6 10 Boltron H20 2.0 8.0Boltron H30 PS, HIPS GEH 28.5 28.5 28.5 28.5 28.5 26.5 22.6 18.5 28.528.5 1897 Liquid FR RDP 16.7 16.7 16.7 16.7 16.7 16.7 16.7 16.7 16.716.7 FR pump TOTAL PARTS 100.1 100.2 100.2 100.2 100.1 100.2 100.2 100.2100.2 100.2 HDT @ 264 psi (1/8″) deg F. Notched Izod, 5.17 5.03 3.062.32 5.40 5.08 3.01 2.08 5.81 2.49 73F, ft-lb/in Total Energy, 30.8 34.328.9 22.8 37.6 38.7 29.4 20.8 34.6 8.6 73F ft-lb Flexural Modulus, 358362 387 367 388 389 393 342 305 73F (1/8″) kpsi Flexural Str. @ 13,51013,160 13,080 13,850 13,850 14,480 15,210 12,710 11,340 yield, 73F(1/8″) psi Tensile Str. @ 8,240 8,520 8,460 8,400 8,490 8,650 9,0809,520 8,220 7,320 yield, 73F 2 in/m/in, Psi T. Str. @ break, 6,860 7,1207,360 7,240 6,700 7,000 7,800 8,830 6,470 6,820 73F 2 in/m/in, psi T.Elongation @ 3.63 3.68 3.44 3.38 3.76 3.76 3.81 3.80 3.74 3.65 yield,73F 2/in/m/in, % T. Elongation @ 11.9 8.7 7.5 7.6 10.2 8.8 7.0 5.5 9.68.3 break, 73F 2/in/m/in, % Kayeness Rheology @ 230° C. position, Pa-sRate (1/s)  100 2032 1764 1360 984 1879 1947 1669 1510 1898 432  600 735852 519 385 716 733 639 588 723 232 1000 467 414 333 248 463 472 414 384489 197 1500 357 315 254 191 357 364 319 297 362 183 Transfer Pressurepsi 1212 1173 1062 883 1037 1154 1064 1040 1145 1126 UL-94 Flammability10 bar statistics 1st ignition Ave. 1.5 1.7 3.8 2.3 1.4 1.4 1.5 1.5 1.73.1 Std. Dev. 0.3 0.5 4.7 1.0 0.3 0.3 0.3 0.4 0.4 3.3 2nd ignition Ave.4.2 3.0 7.6 4.9 5.4 3.4 3.0 2.9 8.2 7.4 Std. Dev. 2.8 1.5 7.5 2.6 3.82.0 1.7 1.2 3.2 6.0 10 Bar Total Ave. 2.9 2.3 5.7 3.6 3.4 2.4 2.2 2.24.0 5.2 Std. Dev. 2.4 1.3 8.4 2.3 3.3 1.7 1.4 1.2 3.2 6.3 Range 1.2-10.01.1-5.4 1.2-26.8 1.3-9.8 1.0-14.3 1.1-8.7 1.1-6.4 1.1-6.0 1.1-11.61.4-23.1 UL Rating V-0 V-0 V-1 V-0 V-0 V-0 V-0 V-0 V-0 V-1 FORMULATION13 14 15 16 17 18 19 20 21 22 .46 IV PPO 40.5 50.5 50.5 50.6 48.5 44.540.5 50.5 50.5 60.5 SBS, Kralon D1101 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.42.4 2.4 LLDPE 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 TDP 0.4 0.4 0.40.4 0.4 0.4 0.4 0.4 0.4 0.4 ZnS 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1ZnO 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 TSAN 0.2 0.2 0.2 0.2 0.2 0.20.2 0.2 0.2 0.2 Nirez 2150/7042 Boltron H20 2.0 6.0 10.0 Boltron H30 2.06.0 10.0 2.0 6.0 10.0 PS, HIPS GEH 26.5 26.5 22.5 18.5 26.5 28.5 26.526.5 22.5 18.5 1897 Liquid FR RDP 16.7 16.7 16.7 16.7 16.7 16.7 16.716.7 16.7 16.7 FR pump TOTAL PARTS 100.2 100.2 100.2 100.2 100.2 100.2100.2 100.2 100.2 100.2 HDT @ 264 psi 187 176 176 175 174 171 169 175178 174 (1/8″) deg F. Notched Izod, 1.04 6.10 2.06 1.62 5.90 2.79 1.425.99 2.06 0.97 73F, ft-lb/in Total Energy, 4.8 36.7 7.8 3.7 34.1 7.0 4.630.4 8.3 3.2 73F ft-lb Flexural Modulus, 266 349 311 354 320 280 359 332284 73F (1/8″) kpsi Flexural Str. @ 8,130 13,170 11,930 12,880 11,540yield, 73F (1/8″) Psi Tensile Str. @ 5,600 8,430 7,690 8,350 7,750 5,2408,660 8,180 4,960 yield, 73F 2 in/m/in, Psi T. Str. @ break, 5,630 6,6907,500 6,560 7,000 5,140 6,790 7,620 5,100 73F 2 in/m/in, psi T.Elongation @ 2.71 3.88 3.70 3.85 3.85 2.30 3.61 3.97 2.11 yield, 73F2/in/m/in, % T. Elongation @ 2.7 10.2 4.9 11.5 8.7 2.5 10.5 7.9 2.6break, 73F 2/in/m/in, % Kayeness Rheology @ 230° C. position, Pa-s Rate(1/s)  100 265 1796 305 296 1289 294 251 1392 266 256  600 111 719 177141 588 199 130 636 199 143 1000 83 467 163 107 394 184 107 438 102 1171500 71 369 162 93 318 180 97 348 192 105 Transfer Pressure psi 768 12411005 — 1150 UL-94 Flammability 10 bar statistics 1st ignition Ave. — 2.12.2 — 2.3 3.2 4.5 2.1 2.4 2.2 Std. Dev. — 0.1 0.8 — 1.4 2.1 4.2 1.0 1.31.0 2nd ignition Ave. — 4.6 5.5 — 11.0 9.6 4.6 4.2 5.2 5.7 Std. Dev. —1.7 4.3 — 9.8 10.1 1.3 2.7 2.7 3.9 10 Bar Total Ave. — 3.3 3.8 — 6.8 8.44.5 3.1 3.8 3.9 Std. Dev. — 1.8 3.5 — 6.0 7.8 2.9 2.3 2.5 3.3 Range —1.2-8.1 1.5-16.9 — 1.2-27.9 1.4-34.0 1.9-11.9 1.3-9.4 1.5-10.4 1.4-11.9UL Rating — V-0 V-0 — V-1 V-1 V-1 V-0 V-0 V-1

[0067] The results in Table 4 show that high flow is still obtained withthe use of the flame retardant additive and that flammability is atacceptable levels with the addition of the dendritic polymers,particularly at the lower loadings of dendritic polymers.

[0068] The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the theseexamples.

[0069] From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

1. A composition comprising: a polyphenylene ether resin, and adendritic polymer having a melt viscosity of 1 to 250 Pa at atemperature of 110° C. and a shear rate of 30 sec⁻¹.
 2. The compositionof claim 1, wherein the polyphenylene resin ispoly(2,6-dimethyl-1,4-phenylene)ether resin or a copolymer of2,6-dimethyl-phenol and 2,4,6-dimethyl phenol.
 3. The composition ofclaim 1, wherein the polyphenylene ether resin has an intrinsicviscosity of more than 0.2 dl/g as measured in chloroform at 25° C., andthe composition contains 30 wt % or less of the dendritic polymer. 4.The composition of claim 1, which comprises 10 wt % or less of thedendritic polymer.
 5. The composition of claim 1, which comprises 6 wt %or less of the dendritic polymer.
 6. The composition of claim 1, whichcomprises 4 wt % or less of the dendritic polymer.
 7. The composition ofclaim 1, which comprises 2 wt % or less of the dendritic polymer.
 8. Thecomposition of claim 1, wherein the dendritic polymer is of a starburstconfiguration and comprises polyester branching units bound to a core.9. The composition of claim 8, wherein the polyester branching units ofthe dendritic polymer have epoxy groups or hydroxy functional groups.10. The composition of claim 9, where in the epoxy or hydroxy groups areat the periphery of the dendritic polymer.
 11. The composition of claim9, where a portion of the epoxy or hydroxy groups on the dendriticpolymer are reacted to provide chain termination or functional groups.12. The composition of claim 1, wherein the dendritic polymer compriseschain extenders.
 13. The composition of claim 12, wherein the chainextenders have at least two hydroxyl groups and are selected from thegroup consisting of α, α-bis (hydroxymethyl)-propionic acid, α,α-bis(hydroxymethyl)-butyric acid, α, α, α-tris(hydroxymethyl)-aceticacid, α, α-bis(hydroxymethyl)-bularic acid, α,α-bis(hydroxymethyl)-propionic acid, α, β-dihydroxypropionic acid,heptonic acid, citric acid, d- tartaric acid or l- tartaric acid,α-phenylcarboxylic acids and combinations comprising at least one of theforegoing chain extenders.
 14. The composition of claim 1, wherein thedendritic polymer has a weight average molecular weight, as determinedby gel permeation chromatography, of 1,000 to 5,000.
 15. The compositionof claim 1, which additionally comprises an alkenyl aromatic resin. 16.The composition of claim 16, wherein the alkenyl aromatic resincomprises polystyrene homopolymers, copolymers of styrene, a rubbermodified polystyrene, or high impact polystyrene.
 17. The composition ofclaim 1, which additionally comprises an impact modifier.
 18. Thecomposition of claim 1, which additionally contains at least oneadditive selected from the group consisting of impact modifiers, flameretardants, plasticizers, antioxidants, fillers, reinforcing agents,stabilizers, antistatic agents, lubricants, colorants, dyes, pigmentsand flow modifiers.
 19. A composition comprising: a polyphenylene etherresin, and a dendritic polymer having asymmetric branches and a meltviscosity of 1 to 250 Pa at a temperature of 110° C. and shear rate of30 sec⁻¹.
 20. The composition of claim 19, wherein the polyphenyleneresin is poly(2,6-dimethyl-1,4-phenylene)ether resin or a copolymer of2,6-dimethyl-phenol and 2,4,6-dimethyl phenol.
 21. The composition ofclaim 19, wherein the polyphenylene ether resin has an intrinsicviscosity of more than 0.2 dl/g as measured in chloroform at 25° C., andthe composition contains 30 wt % or less of the dendritic polymer. 22.The composition of claim 19, which comprises 10 wt % or less of thedendritic polymer.
 23. The composition of claim 19, which comprises 6 wt% or less of the dendritic polymer.
 24. The composition of claim 19,which comprises 4 wt % or less of the dendritic polymer.
 25. Thecomposition of claim 19, which comprises 2 wt % or less of the dendriticpolymer.
 26. The composition of claim 19, wherein the dendritic polymeris of a starburst configuration and comprises polyester branching unitsbound to a core.
 27. The composition of claim 26, wherein the polyesterbranching units of the dendritic polymer have epoxy groups or hydroxyfunctional groups.
 28. The composition of claim 27, wherein the epoxy orhydroxy groups are at the periphery of the dendritic polymer.
 29. Thecomposition of claim 26, where a portion of the epoxy or hydroxy groupson the dendritic polymer are reacted to provide chain termination orfunctional groups.
 30. The composition of claim 19, wherein thedendritic polymer comprises chain extenders.
 31. The composition ofclaim 30, wherein the chain extenders have at least two hydroxyl groupsand are selected from the group consisting of α,α-bis(hydroxymethyl)-propionic acid, α, α-bis(hydroxymethyl)-butyricacid, α, α, α-tris(hydroxymethyl)-acetic acid, α,α-bis(hydroxymethyl)-bularic acid, α, α-bis(hydroxymethyl)-propionicacid, α, β-dihydroxypropionic acid, heptonic acid, citric acid, d-tartaric acid or l- tartaric acid, α-phenylcarboxylic acids andcombinations comprising at least one of the foregoing chain extenders.32. The composition of claim 19, wherein the dendritic polymer has aweight average molecular weight, as determined by gel permeationchromatography, of 1,000 to 5,000.
 33. The composition of claim 19,which additionally comprises an alkenyl aromatic resin.
 34. Thecomposition of claim 33, wherein the alkenyl aromatic resin comprisespolystyrene homopolymers, copolymers of styrene, a rubber modifiedpolystyrene, or high impact polystyrene.
 35. The composition of claim19, which additionally comprises an impact modifier.
 36. The compositionof claim 19, which additionally contains at least one additive selectedfrom the group consisting of impact modifiers, flame retardants,plasticizers, antioxidants, fillers, reinforcing agents, stabilizers,antistatic agents, lubricants, colorants, dyes, pigments and flowmodifiers.